What is html erb

What is erb in HTML?

As @Chowlett mentioned before, erb stands for Embedded Ruby. When you define any file as “. html. erb” that means it’s an HTML file with ruby code embedded in it and it is similar to “. rhtml” extension of rails file.

How do I view HTML erb?

View templates HTML tags provide static web pages only but ERB tags give us dynamic information in that HTML template. To view the template file, go to Rails application >> app >> View>> Home folder where the templates files are available.

What is erb language?

ERB (Embedded RuBy) is a feature of Ruby that enables you to conveniently generate any kind of text, in any quantity, from templates.

What is a Rails form?

Rails provides a series of helpers for generating form elements such as checkboxes, text fields, and radio buttons. These basic helpers, with names ending in _tag (such as text_field_tag and check_box_tag ), generate just a single element. The first parameter to these is always the name of the input.

How do you write HAML?

In Haml, we write a tag by using the percent sign and then the name of the tag. This works for %strong , %div , %body , %html ; any tag you want. Then, after the name of the tag is = , which tells Haml to evaluate Ruby code to the right and then print out the return value as the contents of the tag.

What is JSON ERB?

json. erb is basically the raw json response but with some parts evaluated in ruby. For example, this is a valid json. erb, that produces valid json:

What are locals in Rails?

This means you pass a local instance variable called @buyer to the account partial and the variable in the account partial is called @account . I.e., the hash < :account =>@buyer > for :locals is just used for passing the local variable to the partial.

What is layout in Ruby on Rails?

In Rails, layouts are pieces that fit together (for example header, footer, menus, etc) to make a complete view. An application may have as many layouts as you want. Rails use convention over configuration to automatically pair up layouts with respective controllers having same name.

What is the ERB test?

The multiple choice ERB is a battery of tests designed to provide information about a student’s performance in several key areas (depending on the grade level): listening, verbal reasoning, quantitative reasoning, reading comprehension, word analysis, writing mechanics, and mathematics.

What is local true in Rails form?

The idea behind it is to unify the interface of form_tag and form_for by extracting both implementations to a common object. As long as developers start using this new helper, form_tag and form_for will softly get deprecated.

How do you generate scaffold in Rails?

To generate a fully working scaffold for a new object, including model, controller, views, assets, and tests, use the rails g scaffold command. Then you can run rake db:migrate to set up the database table. Then you can visit http://localhost:3000/widgets and you’ll see a fully functional CRUD scaffold.

How do I run a Haml file?

1. Create a route.
2. Create a controller with an action for that route.
3. Create a view for the controller action.
4. Visit the URL corresponding to the route.

What’s the max number of characters allowed in Erb?

Max number of characters allowed is 27. Transaction updates are input as PSB/MPD/BCT level. Source documents include DD Form 4, DA Form 4187, marriage certificate, divorce decree, etc. References for additional information include DA PAM 600-8 and para 6-21, AR 600-8-104.

What are the different types of ERB courses?

TT (Tour Type): Type of tour completed by Soldier. Codes are as follows: – L = Long Tour – S = Short Tour – C = Combat – O = Operational (Non-combat) – R MOS producing courses are not listed on the ERB. Maximum of 15 military schools. Transaction updates are input at PSB/MPD/BCT level. Source documents include the DA Form 87, Certificate of

What does Erb stand for in military category?

(Combat Deployment ) Defined as an operation in a designated combat zone. O (Operational Deployment) Non-combat overseas deployments other than those designated as a\ combat deployment, such as a peacekeeping/enforcement overseas, e.g. Balkans, Guantanamo

Which is the correct verb for the verb equivalent?

What is the verb for equivalent? (transitive) To be equivalent or equal to; to counterbalance. simple past tense and past participle of equivalise (transitive) To make equivalent to; to equal. Third-person singular simple present indicative form of equivalise simple past tense and past participle of equivalence Find more words!

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Ruby Templating Engines: ERB, HAML & Slim

A templating engine allows you to mix HTML & Ruby so you can generate web pages using data from your database.

ERB is Rails default engine for rendering views.

Note: Rails uses an implementation called erubi instead of the ERB class from the Ruby standard library.

As you’ll learn later in this article, you don’t need Rails to use ERB.

An introduction to ERB’s syntax, how to use ERB in your Ruby projects & how it compares to other templating engines, like HAML.

Embedded Ruby (ERB) Tutorial

An ERB template is a file that ends with an .html.erb or .erb extension.

Everything you write inside an ERB template is HTML.

Unless… you use a special tag!

Here’s an example:

This tag will be replaced by the templating engine by evaluating the Ruby code inside it.

It’s like string interpolation!

Notice the equals sign in .

That tells ERB to render the contents of this tag.

If you want to write a loop or an if statement in ERB you want to leave out the equals sign so ERB doesn’t render things that you don’t need.

You may even get an error if you don’t use the correct ERB tag.

Here’s an example:

Are you a chocolate lover? Here are some of our best PREMIUM chocolate bars! Here are our top 10 snacks that people bought this month.

This is a ERB if statement, like a regular Ruby if statement but wrapped around the special templating syntax so it can be evaluated & replaced by the output when this page is rendered for the user.

Here’s an ERB loop:

Given an array of books, this will print every book with a line break between them.

If you’re using Rails, it will render this template for you when you call the associated controller action.

Using ERB Without Rails

If you want to use ERB outside of Rails to build reports & static websites…

You can do this:

require 'erb' Book = Struct.new(:title, :author) template = ERB.new(File.read('template.erb')) template.result_with_hash(books: [Book.new("test"), Book.new("abc")])

You’ll need to replace @books with books in your template for this to work.

Rails uses a metaprogramming trick called “variable binding”.

That’s how Rails shares instance variables from your controller with your template. But if you’re going to use ERB without Rails using a hash (with result_with_hash method) is a cleaner solution.

Comparing Templating Engines

Let’s compare the different templating engines.

You can access all of these engines using the Tilt gem. Tilt is an adapter gem like Faraday.

require 'tilt' Tilt::ErubiTemplate.new("test.erb").render require 'tilt/haml' Tilt::HamlTemplate.new("test.haml").render require 'slim' Slim::Template.new("test.slim").render

Here’s a benchmark between the different implementations:

Comparison: erubi: 5786.0 i/s ERB: 4438.8 i/s - 1.30x slower Haml: 1340.0 i/s - 4.32x slower Slim: 724.1 i/s - 7.99x slower

Here’s what HAML syntax looks like:

%head %title Ruby Templating Engines = 123 * 2 %body - foo.each do |bar| %p This Is Cool

It’s different from plain HTML, so you’ll need to get used to it.

Even more succinct is Slim’s syntax:

head title Ruby Templating Engines = 123 * 2 body - foo.each do |bar| p | This Is Cool

Slim uses the pipe character for multi-line blocks of content, in Haml you don’t need that.

Let’s take a look at a comparison @ the Github repository level:

REPO	STARS	LAST_COMMIT	LATEST_RELEASE	CREATED_DATE
jeremyevans/erubi	255	2019-11-05 14:09:06	2019-09-25 15:44:36	2016-11-10 22:42:44
haml/haml	3461	2019-12-27 10:51:59	2019-08-06 12:01:09	2008-02-11 22:55:26
slim-template/slim	4898	2019-12-15 23:55:23	2018-09-02 23:54:10	2010-09-13 01:32:07

So which one should you use?

I think it’s mostly personal preference.

But one thing is clear:

Choose one for a specific project & write all your templates using that engine.

I like to stick with ERB templates…

With the right editor snippets & support it’s not that much extra writing.

You even have converters available (from/to ERB) if you ever want to move to another engine.

Summary

You’ve learned about templating engines in Ruby!

Please share this article & subscribe to my newsletter if you haven’t yet (9000+ subscribers) so you can get more awesome content like this.

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What is Erb in HTML?

HTML. ERB is HTML mixed with Ruby, using HTML tags. All of Ruby is available for programming along with HTML.

What are ERB templates?

ERB templates combine plain text with Ruby code for variable substitution and flow control, making them easy to write and maintain. Although ERB is most commonly seen generating Web pages, it is also used to produce XML documents, RSS feeds, source code, and other forms of structured text file.

What is chef template?

Chef uses templates to be able to fill the configuration file with dynamic values. Chef provides templates as a resource which can be used in the recipe. Configuration files’ dynamic values can be retrieved from data bags, attributes or even calculate them by passing them into the template.

How do you write recipes in chef?

To write a Chef recipe, you need to use Ruby language. A recipe consists of resource definitions that will issue instructions to be executed on servers. For more flexibility you can include resource definitions together with Ruby code. Before we can start writing recipes, let us discuss the building blocks of a recipe.

How do I run chef-client?

When the chef-client command runs, it basically undergoes 10 different steps, which we are going to learn in this article.

1. Step 1 — Get configuration data.
2. Step 2 — Authenticate with Chef server.
3. Step 3 — Get/rebuild the node object.
4. Step 4 — Expand the run-list.
5. Step 5 — Synchronize cookbooks.
6. Step 6 — Reset node attributes.

How do you write a Chef Cookbook?

1. In your Chef workstation, Create a new file under the ~/chef-repo/cookbooks/lamp_stack/recipes directory called apache.
2. Open the file, and define the package resource to install Apache: File: ~/chef-repo/cookbooks/lamp_stack/apache.rb.
3. Set Apache to enable and start at reboot.

What does a chef cookbook do?

Cookbooks are fundamental working units of Chef, which consists of all the details related to working units, having the capability to modify configuration and the state of any system configured as a node on Chef infrastructure. Cookbooks can perform multiple tasks.

What is chef cookbooks and recipe?

A Chef cookbook is comprised of recipes that a nodes desired state. Recipes work as a collection of resources that determine the configuration or policy of a node, with resources being a configuration element of the recipe. For a node to run a recipe, it must be on that node’s run list.

What is Chef server?

Chef Server is the center of the workstation and the nodes. All the cookbooks, recipes, and metadata are stored here. The workstation sends the cookbook to the server using a knife. The nodes communicate with the server using the Chef client.

What is chef client?

A chef-client is an agent that runs locally on every node that is under management by Chef. When a chef-client is run, it will perform all of the steps that are required to bring the node into the expected state, including: Registering and authenticating the node with the Chef server.

What are chef resources?

Advertisements. Chef resource represents a piece of the operating system at its desired state. It is a statement of configuration policy that describes the desired state of a node to which one wants to take the current configuration to using resource providers.

What is chef and how it works?

Chef is a configuration management technology used to automate the infrastructure provisioning. It is developed on the basis of Ruby DSL language. It is used to streamline the task of configuration and managing the company’s server. It has the capability to get integrated with any of the cloud technology.

Is Chef a framework?

The Chef framework is basically a combination of the Chef server, node, and workstation. Essentially, these are predefined roles for resources, which are the core components of the automated configuration and deployment process.

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